Wheel starter



Aug. 11, 1936. G, B, slsE R 2,050,741

WHEEL STARTER Filed April 1, 19.32 2 Sheets-Sheet l INVENTOR B fad/k715iJoe/r A'RNEY Aug. 11, 1936. G: B. spam 2,650,741

WHEEL STARTER Filed April 1, 1952 2 Sheets-Sheet 2 v INVENTOR l 6o dfrey5 206/? 8 BY ATTORN EY Patented Aug. 11, 1936 UNITED STATES PATENTOFFICE,

WHEEL STARTER Godfrey B. Speir, Hempstead, N. n, assignor, by

mesne assignments, to Curtiss Aeroplane &'

.Motor Company, Inc., a corporation of York New

Application April 1', 1932, as... 602,614

air, so that when the-airplane lands the wheels are rotating, thusincreasing tire life.

It has been noted for some time that the tires on airplane wheels,particularly on large airplanes, are subject to great wear due tolanding. The landing speed of an airplane is usually from 40 to milesper hour. The wheels of the airplane prior to landing are stationary,and when the initial impact of landing takes place, the wheels mustattain rotation from their contact with the ground. On large wheelshaving large tires, wherein the weight of the wheels and tires isconsiderable, and hence their inertia to rotation is considerable, thetire must necessarily scrape along the ground before it rotates at aspeed equivalent to the speed of the airplane traveling along theground. This scraping wears away the rubber unevenly and causespremature wear of the tires, and also causes a safety hazard due to thelikelihood of punctures or blowouts in landing. Such blowouts in landingmight result in a serious accident.

It has been found in aircraft operation that due to the scraping actionwhen the'tire touches the ground. By providing means to initiaterotation of the wheels just prior to landing, this sdraping eflect islargely overcome and tire life is greatly increased. Most of theseairplanes are equipped with brakes and the brakes are used to bring theairplane to a quick stop after it has landed. However, when the wheel isrotating and the brakes are applied, the wear is distributed evenly overthe tread of the tire, so that premature wear is not caused by thebrakes. The principal source of wear in aircraft tires is in the initialimpact when the rubber is scraped oil,

A further object of my invention is to provide a control mechanismoperable by the pilot of an aircraft, to start rotation of the landingwheels just prior to landing.

A i'urther object of my invention is to provide a compact mechanism,easily streamlined and light in weight which may be combined with alanding wheel to attain the. objects above set forth.

A further object of. my invention is to provide in the rotatingmechanism a control means is necessary to wind it.

2 Claims. (Cl. 244-2) whereby the rotating mechanism may be wound orprepared for landing, locked in a wound position, and released instantlyto initiate rotation. The winding operation is possible while the air-''plane is taxiing in a forward direction on the s groundso that noreversal of the mechanism Further objects will be apparent from a reading of the subjoined specification and claims. and from a considerationof the drawings.

In order'to explain the invention more clear- 1y, one embodiment'thereofis shown-in'the accompanying drawings, in which:

Fig.1 is a section of an airplane landing wheel in which is included myinvention; 15

Fig. 2 is an elevation of the landing wheel of Fig. 1 with parts brokenaway tO'ShOW the assembly;

Figs. 3, 5 and 7 are detail sectional views showing the controlmechanism in difierent positions 20 of adjustment; and

Figs. 4, 6 and 8 are sectional elevations onthe 1 lines 4-4, 6-4 and 8.8of Figs. 3, 5 and 7, re: spectively.

Similar parts are indicated in various drawings by similar numbers.

Referring to Fig. 1, an airplane wheel l0 is shown as'mounted on an axleH which in turn is mounted on a strut All. Rotation and loads betweenthe wheel l0 and the axle II. are assumed by the bearings 4 Thev wheelitself comprises a hub portion It with spacing discs 42 and 43 whichcarry a rim l3 on whichis mounted a tire II. The innerfiange of the hubi4 is carried radially outward from the rotational axis of the wheel illto support a brake drum l5. Inside of the brake drum l5 isample spacefor the inclusion of a conventional brake mechanism, the bands of whichare shown in Figs. 3, 5 and lat IS. The brake mechanism. is anchored onan anchor plate i1 supported by a flange It on the strut 40;

Exteriorof the brake band i5 is located an annular channel member l9,which is free to rotate on the exterior surface of the brake drum 45 I5.The annular channel member l9 comprises a cylindrical portionparallel tothe axis of the wheel and bearing upon the brake drum I5, a radial ringportion and an outer cylindrical por-- tion turning in toward the wheel.A spiral spring 2i similar to a clock spring is attached at its innerend to the annular channel member l9, so that the leaf of the spring 2iretreats from the direction of .rotation of the wheel. A ring 22 ispositioned within the outer flange of the channel member l9 and is freeto rotate with respect thereto. The other end of the spring 2| isattached to the ring 22 as shown in Fig. 4. A flexible wheel 23 is keyedat the points 24 to the inner portion of the channel member 9 andthusrotates with said member. This wheel is made in 'the form of aspoked wheel as an independent unit with respect to the wheel. Likewise,the outer ring 22 may turn with respect to the channel member IS, withthe spring 2| joining these two elements so that any movement betweenthe channel member l9 and the ring 22 is proportional to the tension inthe spring 2|. 3

A control mechanism for thespring, channel member and ring is formed byan anchor block 21 fixed to the brake anchor plate II. In this anchorblock is positioned. a control bar 26 arranged to slide through theblock 2'! in a direction parallel to the wheel axis. At the inner end ofthe control bar 26 is a pivot 31 connected to a bell crank 38 pivoted inthe strut 48, from which a control rod 39 passes to the cockpit of theairplane within reach of an occupant thereof. To the control bar. 26 ispivoted a pawl 38 which is adapted to engage in a slot 28 cut in theouter flange of the channel member l9. By means of thispawl, the channelmember I9 is allowed to rotate in a direction similar to the directionof normal rotation of the wheel, but is prevented from rotating in theopposite direction by the engagement of the pawl 38 within the slot 28.On the outer surface of the ring 22 -is pivoted a pawl 3|. locked andwinding positions, the pawl 3| lies close to the ring 22 as shown inFigs. 3, 4, 7 and 8, and engages the control bar 26 so that rota-- tionof the ring 22 in the direction of wheel rotation is prevented. Uponslidably withdrawing the control bar 26 as shown in Fig. 5, the bar isdisengaged from the pawl 3| allowing the outer ring 22 to rotate in thedirection of the wheel rotation. The pawl 3| is adapted to swingradially outward about its pivot by centrifugal force due to rotation ofthe ring 22, when the control bar 26 has been withdrawn. Upon itsoutward extension, the pawl 3| engages with the lugs l8 formed as partof the rim l3 of the wheel ID, as shown in Figs. 5 and 6.

The control bar 26 is adapted to slide toward the wheel |8 so that theroller 33 at the inner end of the control bar 26 may engage the rim 25of the fiexible wheel 23. By pressing the control bar 26 against the rim25, the rim 25 as shown in Fig. 7 engages the friction lining 36 on thewheel disc 43.

In the anchor block 21 is locateda spring keeper 28 adapted to engage inthe notches 34 and 35 in the control bar 26.

Operation of the device involves three positions and three functions.The first function shown in Figs. 3 and 4 is that of locking themechanism out of engagement with thewheel, and also of locking thespring in a wound condition. In Fig. 3 it will be seen that the controlbar is located so that the keeper 28 engages in the notch 34. The pawl38 carried by the bar control bar.

Inits 26 engages in the slot 28 in the channel I6, pre-. ventingcounter-clockwise motion of said channel under the influence of thespring 2|. The pawl 3| on the ring 22 engages the control bar 26,preventing clockwise rotation of the ring 6 22, which rotation is urgedby the spring 2|. This is shown in section in Fig. 4, indicating alsothat the wheel rim and its lug I6 is free to rotate with respect to thespring motor comprised by the channel member I9, the spring 2| and thering 22.

The second function of the device is to allow a release of the springmotor to cause initial rotation of the wheel. This would be done by anoccupant of the airplane prior to making a 15 landing, so that when thewheels contact the ground, they will be rotating. The position of thecontrol mechanism is shown inFigs. 5 and 6. The control bar 26 iswithdrawn so that the keeper 28 registers with the notch 35 in the, 20

As an additional safety factor, a stop 29 abuts the anchor block 21 toprevent withdrawal .of the control bar 26. In this position of thecontrol bar, its inner end carrying the roller 33 is withdrawn free ofthe pawl 3|, 25 allowing the outer ring 22 to be rotated by means of thetension of the spring 2|. In this position, likewise, the pawl 38continues toengage in the slot 28 thereby, holding the inner end of thespring 2| against reactional rota- 30 of the energy in the spring,although the wheel 40 -may continue to rotate, the rim lugs l8 willoverrun the pawl 3|, knocking it back into its position adjacent thering 22 and thus allowing the ring 22 to come to rest although the wheelmay still be rotating. At this time, the control bar. 26 may be moved tothe locked position shown in Fig. 3 or may be moved to the position toinduce rewinding of the spring, shown in Fig. 7. If desired, a springresilient enough to be overcome by centrifugal force may be locatedadjacent to the pawl 3| to hold it normally against the' ring 22.

The rewinding operation may be conducted while the airplane is taxiingalong the ground, wherein positive rotation of the wheel is assured byits rolling under the power of the engine and propeller. The control bar26 is thrust inward, so that the roller 33 engages the rim 25 of theflexible wheel 23, pushing it against the friction lining 36. In thisposition of the 0 control bar, the outer ring 22 is locked againstclockwise rotation, since the pawl 3| engages the control bar 26. Thecontact of the flexible wheel 23 with the friction lining 36 causesrotation of the channel member |9 in a clockwise 435 direction, throughthe fact that the wheel 23 is keyed to the channel member at the point24. Rotation of the channel member is possible through the disengagementof the pawl 38 from the slot 28. This-causes winding of the spring. 7When a suflicient degree of tension is reached in winding the spring,pressure may be relaxed upon the control bar 26 thus allowingdisengagement of the friction surfaces, whereupon the pawl 38 willimmediately engage in the slot 20 and lock the spring motor in a woundposition. Slight retraction of the control bar 26 permits engagement ofthe keeper 28 in the notch 34, thus setting the mechanism in the sameposition shown in Fig. 3. As above mentioned, when the keeper 28 engagesin the notch 34, the spring motor is held in a locked and wound positionand is likewise entirely out of engagement with the wheel so that thelatter is free to rotate for taking off and so that the brakes l8 maybeapplied in a normal manner against the inside of the brake drum l5.This, in eiTect, gives a spring motor for initiating rotation of thewheels in the air and allows winding and locking of the spring motorwhile taxiing on the ground, all functions-releasing, winding andlocking being possible with continuous forward rotation of the wheel.

The embodiment shown comprises essentially a spring motor and controlmeans for operating it. I do not wish to limit my invention, however, toa spring motor. Electric motors, inertia starters and similar devicesmay be used with beneficial effect to accomplish the objects set forth,namely, to provide a means for initiating rotation of the wheel in theair, and

prior to landing, to minimize tire wear. By my device I eliminatecontinuous rotation of the wheel in the air, which rotation isunnecessary,

and causes unnecessary wear on and throwing oil of lubricant from thewheel bearings.

While I have described my invention in detail in its present preferredembodiment, it will beobvious to those skilled in the art, afterunderstanding my invention, that various changes and modifications maybe made therein without 5 departing from the spirit or scope thereof. Iaim in the appended claims to cover all such modifications and changes.

I claim as my invention:

1. In an airplane, a landing wheel; .a spring motor comprising aspring,.an annular channel member embracing said spring and adjacent toand revoluble with respect to said wheel, means for engaging saidchannel member in driven relation to said wheel, an outer ring attachedto said spring, and means to connect said outer ring in driving relationto said wheel.

2. In an airplane, a landing wheel; a spring motor comprising a spring,an annular channel member embracing said spring and adjacent to andrevoluble with respect to said wheel, means for engaging said channelmember in driven relation to said wheel, an outer ring attached to saidspring, means to connect said outer ring, in driving relation to saidwheel; and control means selectively operable to effect saiddrivenrelation, said driving relation, and to lock said engaging means andsaid connecting means out of engagement with said wheel.

GODFREY B. SPEIR.

